[Bug libstdc++/124290] 23_containers/mdspan/submdspan tests time out

[ro at CeBiTec dot Uni-Bielefeld.DE]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124290

--- Comment #2 from ro at CeBiTec dot Uni-Bielefeld.DE <ro at CeBiTec dot Uni-Bielefeld.DE> ---
> --- Comment #1 from Tomasz Kamiński <tkaminsk at gcc dot gnu.org> ---
> Yes, adding `dg-timeout-factor` seem as reasonable solution, and few sibling
> test in the same directory already have them.
>
> For the splitting, the test were already split to test one layout per file, so
> without large refactoring of them, I do not think further splitting is
> feasible.
>
> Would you mind posting a patch with factors that make test pass for you?

Sure, I'll give it a try.  I'll check if there's a specific set where
this happens repeatedly or if I just add dg-timeout-factor 2 to all of
them (so it won't be forgotten for future tests ;-)  After all, the
tests that time out varies from build to build.